I don't think the photos are of the production model that will be released, but it probably is a real prototype. If that is going to be the new design, I'm sure there will be some tweaks to it, to make it look nicer. If they were to keep that form factor, the production model will probably have no seams, be a bit slimmer, etc. That could just be an unfinished model in the beginning stages. I would be VERY surprised if that is the exact look of the next iPhone that is going to be released.
How thin do people want their phone to be FFS? It's already been shown that this prototype is slimmer than the 3GS.
I used the Nexus One for a few days and thinner is definitely not better.